The preparation of ester derivatives of sulfonic acids can be carried out by heating the solid sodium salt of the acid with dimethyl or diethyl sulfate.
Sulfonic acid esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. This method is used for the conversion of alcohols to tosylates, brosylates and similar sulfonic acid esters. The alcohols may be either aliphatic or aromatic. The base is usually pyridine which functions as a nucleophilic catalyst. See Frieser and Frieser, Ref. 411, Vol. 1, page 1180 (1967).
The aryl sulfonates are sometimes useful for the purposes of identification or as a leaving group in nucleophilic substitution reactions.
While the prior art methods for the preparation of these esters are satisfactory, they provide long reaction times and tedious workup. Additionally, since aqueous separations are required, isolation of the desired product is inconvenient. Yields of the esters are adversely affected.
It is desirable, therefore, to have available a process for producing these toluenesulfonic acid esters that allows easy separation of the product in increased yields and shorter reaction times.